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EC6611 COMPUTER NETWORKS LAB

VVIT DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING

Dharmapuri – 636 703

Regulation : 2013

Branch : B.E. – ECE

Year & Semester : III Year / VI Semester

ICAL ENG

LAB MANUAL

EC6611- COMPUTER NETWORKS LABORATORY



ANNA UNIVERSITY CHENNAI

REGULATION - 2013

EC6611- COMPUTER NETWORKS LABORATORY

1. Implementation of Error Detection / Error Correction Techniques

2. Implementation of Stop and Wait Protocol and sliding window

3. Implementation and study of Go back-N and selective repeat protocols

4. Implementation of High Level Data Link Control

5. Study of Socket Programming and Client – Server model

6. Write a socket Program for Echo/Ping/Talk commands.

7. To create scenario and study the performance of network with CSMA / CA Protocol

and compare with CSMA/CD protocols.

8. Network Topology - Star, Bus, Ring

9. Implementation of distance vector routing algorithm

10. Implementation of Link state routing algorithm

11. Study of Network simulator (NS) and simulation of Congestion Control Algorithms

Using NS

12. Encryption and decryption.

TOTAL : 45 PERIODS



INDEX

EX.NO DATE LIST OF EXPERIMENTSSTAFF

SIGINATURE REMARKS

1 Implementation of Error Detection / ErrorCorrection Technique

2 Implementation of Stop and Wait Protocol

3 Implementation of Sliding Window Go Back N

4 Implementation and study of sliding windowSelective repeat protocol.

5 Study of Socket Programming And Client –Server Model

6 Write a Socket Program for Echo Commands

7 Write a Socket Program for Ping Commands

8 Write a Socket Program for Talk Commands

9 Implementation of Distance Vector RoutingAlgorithm

10 Implementation of Link State RoutingAlgorithm

11 Implementation and Study the Performance of

Network with CSMA / CA Protocol

12 Implementation and Study the Performance of

Network With CSMA/CD Protocols

13

Implementation of Data Encryption and

Decryption

14

Study of Network Simulator (Ns) and

Simulation of Congestion Control Algorithms

Using NS

15 Network Topology - Token Bus

16 Network Topology - Token Ring

17 Implementation of High Level Data LinkControl



INTRODUCTION

COMPUTER NETWORKS LABORATORY

A computer network is an interconnection of various computers to share software, hardware,

resources and data through a communication medium between them. A Computer Networking is a set

of autonomous computers that permits distributed processing of the information and data and increased

Communication of resources .Any Computer Networking communication need a sender, a receiver and

a communication medium to transfer signal or Data from sender to the receiver. We need sender,

receiver, communication channel, protocols and operating system to establish a computer networking.

A networks model describes the organization of various computers in a network for using resources.

A computer networks communication can be based on centralized, distributed or collaborative

computing. Centralized computing involves many workstations or terminals, connected to one central

mainframe or other powerful computer. Distributed computing interconnects one or more personal

computers and allows various services like Data sharing, hardware sharing resources sharing or

network sharing. The collaborative computing is the combination of centralized and distributed

computing.

1. Centralized computing.

• It is also known as client-server computing.

• In this type of system, multiple computers are joined to one powerful mainframe computer.

• The server or mainframe computer has huge storage and processing capabilities.

• The computers that are connected to the mainframe or server are called Clients or Nodes.

• These nodes are not connected to each other; they are only connected to server.

2. Distributed computing

• If one computer can forcibly start, stop or control another computers are not autonomous. A

system with one control unit and many slaves, or a large computer with remote printers and a

terminal is not called a computer network; it is called a Distributed System.

• Distributed computing means that the task is divided among multiple computers.

• Distributed computing interconnects one or more personal computers or Workstations.

• In distributed computing, the nodes are capable of processing their own data and rely on

network for services other than data processing.

• It allows various services like network sharing, hardware sharing and file sharing.



3. Collaborative computing / Hybrid computing

• It is the combination of centralized and distributed computing

Hybrid computing

In collaborative computing, the nodes are able to serve the basic needs of their users but they

are dependent on some other computers for processing some specific request.

Computer Network Classification:

The local area network communication can be constructed by using server based model or peer

to peer model. In peer to peer networks, the individual clients share data and resources but no one

computer is treated as server. Networks can be classified into local area Networks, metropolitan area

Networks and wide area networks. Local area network is the small network that covers a small area of

Network. Metropolitan area networks are created by combining various local area networks. Wide area

networks are the biggest networks that provide connectivity across the globe. Networks provide the

benefits of exchanging information or Data, sharing resources, reducing system costs, increased

reliability and flexible working environment.



Computer Network topology:

The physical arrangement of computers in a communication network is called as topology. In

star topology, every system on the network is connected to a central controller called Hub and all the

data is transmitted through this. Star topology is very easy to install and configure. In bus topology, a

single cable acts as a backbone of the communication network and all the nodes or computers are

attached to it by using T connectors.

Uses of Computer Networks:

The computer networks are playing an important role in providing services to large

organizations as well as to the individual common man.

Service Provided by the Network for Companies:

• Many organizations have a large number of computers in operation. These computers may bewithin the same building, campus, city or different cities.

• Even though the computers are located in different locations, the organizations want to keep

track of inventories, monitor productivity, do the ordering and billing etc.

• The computer networks are useful to the organizations in the following ways:

1. Resource sharing.

2. For providing high reliability.

3. To save money.

4. It can provide a powerful communication medium.



1. Resource sharing

• It allows all programs, equipments and data available to anyone on the network irrespective ofthe physical location of the resource and the user.

Resource sharing

2. High reliability due to alternative sources of data:

• It provides high reliability by having alternative sources of data. For e.g. all files could bereplicated on more than one machines, so if one of them is unavailable due to hardware failure

or any other reason, the other copies can be used.

• The aspect of high reliability is very important for military, banking, air traffic control, nuclearreactor safety and many other applications where continuous operations is a must even if there

are hardware or software failures.

3. Money saving:

• Computer networking is an important financial aspect for organizations because it savesmoney.

• Organizations can use separate personal computer one per user instead of using mainframe

computer which are expensive.

• The organizations can use the workgroup model (peer to peer) in which all the PCs arenetworked together and each one can have the access to the other for communicating or sharing

purpose.

• The organization, if it wants security for its operation it can go in for the domain model inwhich there is a server and clients. All the clients can communicate and access data through the

server.



CLIENT - SERVER BLOCK MODEL:

Client -Server

Client: The individual workstations in the network are called as clients.

Server: The central computer which is more powerful than the clients and which allows the

clients to access its software and database is called as the server.

• Server computers typically are more powerful than client computers or are optimized to

function as servers.

• The whole arrangement is called as client -server model.



EX.NO:1

DATE:

AIM:Write a program for error detection and error correction techniques by Hamming Method using

C language.

APPARATUS REQUIERD:

C -editor

Standalone desktop.

PROCEDURE:

1. Start the program.

2. Open C-editor.

3. Type the C program.

4. Save the program with file name ext .c

5. Run the program.

6. If any error occurs in the program correct the error and run it again.

7. Enter the data of 4 bit size message bit.

8. Check the entered data.

9. Stop the program.

IMPLEMENTATION OF ERROR DETECTION / ERROR CORRECTION TECHNIQUES



PROGRAM FOR HAMMING METHOD :

#include<stdio.h>. #include<conio.h>

Void main() {int data[7],rec[7],i,c1,c2,c3,c;printf ("this works for message of 4bits in size \n entermessage bit one by one: ");scanf ("%d %d %d %d",& data[0],&data[1],&data[2],&data[4]);data[6]=data[0]^data[2]^data[4];data[5]=data[0]^data[1]^data[4];data[3]=data[0]^data[1]^data[2];printf("\n the encoded bits are given below: \n");for (i=0;i<7;i++) {printf("%d ",data[i]);}printf("\n enter the received data bits one by one: ");for (i=0;i<7;i++) {

scanf("%d",& rec[i]);}c1=rec[6]^rec[4]^rec[2]^rec[0];c2=rec[5]^rec[4]^rec[1]^rec[0];c3=rec[3]^rec[2]^rec[1]^rec[0];c=c3*4+c2*2+c1 ;if(c==0) {

printf ("\n congratulations there is no error: ");} else {

printf("\n error on the position: %d\n the correctmessage is \n",c);

if(rec[7-c]==0)rec[7-c]=1; elserec[7-c]=0;

for (i=0;i<7;i++) {printf("%d ",rec[i]);

}}

getch();}}



MODEL OUTPUT:

RESULT:

Thus the Error detection and correction methods were executed and verified successfully

by using c – editor.



EX.NO:2

DATE:

AIM:

To implement a Stop & Wait protocol by parallel port & LAN port interface using LAN-T

software to Provide reliable data transfer between two nodes over an unreliable networks.

APPARATUS REQUIERD:

• LTS-01 trainer kit and LAN-T Software

• 2 Computers with Windows XP and Ethernet port available on them

• RJ-45 to RJ-45 LAN connecting cables.

PROCEDURE:

1. Click on the Stop & Wait icon from the desktop on both PCs.

2. Click the Configuration button in the window in both the Pc’s.

PC 1 SENDER PC 2 RECEIVER

3. Click OK button and Download the driver to the NIU using the BOOT button Command.

IMPLEMENTATION OF STOP AND WAIT PROTOCOL



4. Run the experiment by clicking run button or by choosing RUN start from each application.

5. Set the Timeout Value to 1500 ms.

PC1 SENDER PC2 RECEIVER

6. Note down the no of successfully Transmitted Packets.

7. Repeat the above steps for various time out values and plot the graph between timeout

Value & Throughput. Find the optimum timeout value from the plot.

Calculation of Throughput (X):

(Successfully Tx packets count * Packet Length * 8)X = -------------------------------------------------------------

(Duration of Experiment * Data rate)



MODEL GRAPH :

MODEL TABULATION:

Time out value in ms Successfully Tx packets X - Throughput

RESULT:

Thus the Stop & Wait protocol using parallel port & LAN port interface was implemented and

the parameters measured by using LAN-T simulation software.



EX.NO:3

DATE:

IMPLEMENTATION OF SLIDING WINDOW GO BACK N

AIM:

To implement a Sliding Window Go Back N & LAN port interface to Provide reliable data

transfer between two nodes over an unreliable network using LAN-T software.

APPARATUS REQUIERD:



• RJ-45 to RJ-45 LAN connecting cables

PROCEDURE:

1. Click on the Sliding Window GBN icon from the desktop on both PCs.

2. Click the Configuration button in the window in both the Pc’s.




. Click OK button and Download the driver to the NIU using the BOOT button command.

Booting from any one of the applications is enough.

4. Run the experiment by clicking button or by choosing RUN _ start from each application.



6. Note down the no. of successfully Transmitted Packets.

7. Repeat the above steps for various time out values and plot the graph between timeout

Value & throughput and find the optimum time out value from the plot.



Calculation of Throughput (X):

(Successfully Tx packets count * Packet Length * 8)

X = ---------------------------------------------------------------------------------


MODEL GRAPH:

MODEL TABULATION:

Time outvalue in ms

SuccessfullyTx packets

PracticalThroughput



RESULT:

Thus the Sliding Window Go Back N & LAN port interface was implemented and the

parameters measured by using LAN-T simulation software.



EX.NO:4

DATE:

IMPLEMENTATION AND STUDY OF SLIDING WINDOWSELECTIVE REPEAT PROTOCOL.

AIM:

To study and implement the sliding window selective repeat protocol to Provide a reliable data

transfer between two nodes over an unreliable network using LAN-T Software.

APPARATUS REQUIERD:




PROCEDURE:

1. Click on the Selective Repeat icon from the desktop on both PCs.

2. Click the Configuration button in the window in both the Pc’s

PC SENDER 1 PC SENDER 2



SETTING THE CONFIGURATION MENU:

3. Click OK button and Download the driver to the NIU using the BOOT button command.


4. Run the experiment by clicking run button or by choosing RUN start from each application.


6. Note down the no. of successfully Transmitted Packets.

7. Repeat the above steps for various time out values and plot a graph between timeout Value

& Throughput and find the optimum timeout value from the plot.

Calculation of Practical Throughput:

(Successfully Tx packets count * Packet Length * 8)X = ---------------------------------------------------------------------------------


PC 1 PC 2Node ID 0 Node ID 0

Protocol CSMA/CD Protocol CSMA/CDBaud Rate 8Kbps (At both the

configure menu and NEU)Baud Rate 8Kbps (At both the config

menu and NEU)Duration 100s Duration 100sPacket Length 100 bytes Packet Length 100 bytesBit Delay 0(at NEU) Bit Delay 0(at NEU)Direction Sender Direction ReceiverNo of packets 4 No of packets 4IPD 400 IPD 0



MODEL GRAPH :

MODEL TABULATION:

Time outvalue in ms

SuccessfullyTx packets

PracticalThroughput

RESULT:

Thus the sliding window selective repeat protocol for data transfer between two nodes over an

unreliable network through parallel port & LAN port interface was implemented and studied by using

LAN-T simulation software.



EX.NO:5

DATE:

STUDY OF SOCKET PROGRAMMING AND CLIENT – SERVER MODEL

AIM:

To write a program and study of socket programming and client – server based model by using

JDK tool kit software.

APPARATUS REQUIERD:

Personal computer

JDK Tool kit 5.0

PROCEDURE:

Server:

Create a server socket and bind it to port.

Listen for new connection and when a connection arrives, accept it.

Send server‟s date and time to the client.

Read client‟s IP address sent by the client.

Display the client details.

Repeat steps 2-5 until the server is terminated.

Close all streams.

Close the server socket.

Stop.

Client: Create a client socket and connect it to the server‟s port number.

Retrieve its own IP address using built-in function.

Send its address to the server.

Display the date & time sent by the server.

Close the input and output streams.

Close the client socket.

Stop.



PROGRAM FOR CLIENT – SERVER MODEL:

//SERVER

import java.net.*;

import java.io.*;

import java.util.*;

class tcp date server

{

Public static void main (String arg [])

{

Server Socket ss = null;

Socket cs;

Print Stream ps;

Buffered Reader dis;

String inet;

try

{

ss = new Server Socket(4444);

System. Out. Print ln ("Press Ctrl+C to quit");

While (true)

{

cs = ss.accept();

ps = new Print Stream (cs. get Output Stream());

Date d = new Date () ;

ps. println(d);

dis = new Buffered Reader(new Input Stream Reader

(cs .get Input Stream ()));

inet = dis.read Line();

System.out.println ("Client System/IP address is :"+ inet);

ps.close ();

dis.close ();

}

}catch (IO Exception e)

{System.out .println ("The exception is:" + e);



}

}

}

// CLIENT

import java.net.*;

import java.io.*;

class tcpdateclient

{

public static void main (String args[])

{Socket soc; Buffered Reader dis;

String sdate; Print Stream ps;

try { Inet Address is = Inet Address. get Local Host();

if (args.length == 0)

soc = new Socket(InetAddress.getLocalHost(),4444);

else soc = new Socket (Inet Address.

Get By Name (args[0]),4444);

dis = new Buffered Reader

(new Input Stream Reader(soc. Get Input Stream()));

Sdate=dis. read Line ();

System.out.println ("The date/time on server is : " +sdate);

ps = new Print Stream(soc. get Output Stream());

ps.println (is);

ps. close();

catch (IO Exception e)

{

System.out.println ("THE EXCEPTION is :" + e);

}

}

}



OUTPUT:

//SERVER

C:\Documents and Settings\ADMIN>cd C:\Java\jdk1.6.0_02\bin

C:\Java\jdk1.6.0_02\bin>javac tcpdateserver.java

C:\Java\jdk1.6.0_02\bin>java tcp date server

Press Ctrl+C to quit

Client System/IP address is: SYSTEM-35/192.168.1.45

//CLIENT

C:\Documents and Settings\ADMIN>cd C:\Java\jdk1.6.0_02\bin

C:\Java\jdk1.6.0_02\bin>javac tcpdateclient.java

C:\Java\jdk1.6.0_02\bin>java tcpdateclient

The date/time on server is: Thu Mar 12 10:54:41 IST 2015

C:\Java\jdk1.6.0_02\bin>

RESULT:

Thus the socket programming and client – server based model was studied and verified by using

JDK tool kit software.



EX.NO:6

DATE:

WRITE A SOCKET PROGRAM FOR ECHO COMMANDS

AIM:

To write a java program for echo commands using socket programming

APPARATUS REQUIERD:

JDK TOOLKIT 5.0

Standalone desktop.

Echo server:


2. Import java.net and other necessary packages.

3. Create objects for Data Input Stream, Socket and Print Writer to receive client message and

send it back.

4. Store the message in a string and print the message using print () method.

5. Send the same received message to the client using Print Writer and Socket.

6. When the received character is ‘.’, then stop sending the data back.


Echo Client:



3. Create objects for Server Socket and Socket to send the message.

4. Create objects for Print Stream to write message from client to server.

5. Get the user input and store it in a string.

6. Print the string in the Socket using Print Stream to be received by the server.

7. Using the Print () method, receive the client echo message and print it.

8. If the user input is ‘.’, then stop sending the data.




PROGRAM FOR ECHO CLIENT

Echo Serve:

import java.io.*;import java.net.*;class echoserver{public static void main(String args[]){try{Socket s=null;ServerSocket ss=new ServerSocket(8000);s=ss.accept();System.out.println(s);BufferedReader br=new BufferedReader(newInputStreamReader(s.getInputStream()));PrintWriter print=new PrintWriter(s.getOutputStream());int i=1;while(i>0){String str=br.readLine();if(str.equals("."))break;System.out.println("msg received by client:"+str);print.println(str);print.flush();}}catch(IOException e){System.out.println("\n error:"+e);}}}



PROGRAM FOR ECHO CLIENT:

import java.io.*;

import java.net.*;

class echoclient

{

public static void main(String a[])

{

try

{

Socket s=new Socket("LocalHost",8000);

DataInputStream in=new DataInputStream(System.in);

BufferedReader br1=new BufferedReader(newInputStreamReader(System.in));

BufferedReader br2=new BufferedReader(newInputStreamReader(s.getInputStream()));

PrintWriter print=new PrintWriter(s.getOutputStream());

System.out.println("\n msg to be echo:");

String str=br1.readLine();

print.println(str);

print.flush();

System.out.println(br2.readLine());

}

catch(UnknownHostException e)

{}

catch(IOException e)

{

System.out.println("\n error:"+e);

}}}



OUTPUT:

Echo client:

C:\Documents and Settings\Vvit staff>cd\

C:\>cd D:\Sasi\Java

D:\Sasi\Java> set path=c:\program files\java\jdk1.6.0_02\bin

D:\Sasi\Java>javac echoclient.java

D:\Sasi\Java>java echo client

Msg to be echo:

GOD IS GREAT

GOD IS GREAT

D:\Sasi\Java>

ECHOSERVER:

C:\Documents and Settings\Vvit staff>cd\

C:\>cd D:\Sasi\Java

D:\Sasi\Java> set path=c: \b program files\java\jdk1.6.0_02\bin

D:\Sasi\Java>javac echoserver.java

D:\Sasi\Java>java echo server

Socket[addr=/127.0.0.1, port=1623,local port=8000]

msg received by client: GOD IS GREAT

D:\Sasi\Java>

RESULT:

Thus the java Socket Program for Echo Commands is executed and output is verified successfully.



EX.NO:7

DATE:

WRITE A SOCKET PROGRAM FOR PING COMMANDS.

AIM:

To write a java program for Ping commands of socket programming.

APPARATUS REQUIERD:

JDK TOOLKIT 5.0

Standalone desktop.

PROCEDURE:

PING Server:



3. Initialize the ping server with both sockets as null value.

4. Start the server socket.

5. At the client give the IP address of the server.

6. The client program is then started by starting socket.

7. At the receiver end, the client is pinged.


PING Client:



3. Initialize the ping client with both sockets as null value.

4. Start the socket.

5. Get the IP address of the server.

6. Ping the server.

7. At the receiver end, the server is pinged.




PROGRAM FOR PING SERVER:import java.io.*;import java.net.*;public class pingserver{public static void main(String a[]){String line1,line2;int i;ServerSocket es;DataInputStream di;PrintStream ps;Socket csoc;es=null;csoc=null;try{es=new ServerSocket(9999);}catch(Exception e){System.out.println(e);}System.out.println("ping server");try{csoc=es.accept();di=new DataInputStream(csoc.getInputStream());ps=new PrintStream(csoc.getOutputStream());for(i=0;i<4;i++){line1=di.readLine();System.out.println("pinged by client");ps.println(line1+"reply from host:bytes=3<time<1ms TT<=128");}di.close();ps.close(); }catch(Exception e){System.out.println(e);} } }



PROGRAM FOR PING CLIENT:

import java.io.*;import java.net.*;public class pingclient{public static void main(String args[]){PrintWriter out=null;int i,j,k;BufferedReader networkIn=null;try{System.out.println("enter the IP address:");DataInputStream in = new DataInputStream(System.in);String ip = in.readLine();Socket thesocket = new Socket(ip, 9999);networkIn = new BufferedReader(newInputStreamReader(System.in));out = new PrintWriter(thesocket.getOutputStream());System.out.println("\npinging" + ip + "with 32 bytes ofdata\n");for (i = 0; i < 4; i++){out.println(ip);out.flush();String inp = networkIn.readLine();if (inp != null){for (j = 0; j < 10000; j++){for (k = 0; k < 50000; k++){}}System.out.println("reply from" + inp);}else{for (i = 0; i < 4; i++){for (j = 0; j < 10000; j++){for (k = 0; k < 50000; k++){}System.out.println("\nrequest time out");}}}}



}catch (IOException e){for (i = 0; i < 4; i++){for (j = 0; j < 1000; j++){for (k = 0; k < 5000; k++){}}System.out.println("\nrequest timed out");}}try{if(networkIn!=null)networkIn.close();if(out!=null)out.close();}catch(Exception e){System.out.println("\nrequested time out");}}}



OUT PUT:

PING ClientC:\Documents and Settings\Vvit staff>cd\C:\>cd D:\Sasi\JavaD:\Sasi\Java> set path=c:\program files\java\jdk1.6.0_02\binD:\Sasi\Java>javac pingclient.javaD:\Sasi\Java>java ping client

enter the IP address:192.168.1.10pinging192.168.1.10with 32 bytes of data5reply from58reply from89reply from94reply from4D:\Sasi\Java>PING Server

C:\Documents and Settings\Vvit staff>cd\C:\>cd D:\Sasi\JavaD:\Sasi\Java> set path=c:\program files\java\jdk1.6.0_02\binD:\Sasi\Java>javac pingserver.javaD:\Sasi\Java>java ping server

ping serverpinged by clientpinged by clientpinged by clientpinged by clientD:\Sasi\Java>

RESULT:

Thus the java Socket Program for ping Commands is executed and output is verified successfully.



EX.NO:8

DATE:

WRITE A SOCKET PROGRAM FOR TALK COMMANDS.

AIM:

To write a program for talk commands using socket programming to send and receive messagefrom client and server using connection oriented service.

APPARATUS REQUIERD:

JDK TOOLKIT 5.0

Standalone desktop

PROCEDURE:Server:

1. Start the program.2. Create server and client sockets.3. Use input streams to get the message from user.4. Use output stream to send message to the client.5. Wait for client to display this message and write a new one to be displayed by the server.6. Display message given at client using input streams read from socket.7. If in the message given by server or client, the word “end” is encountered, exit both the

programs.8. Stop the program.

Client:1. Start the program.2. Create a client socket that connects to the required host and port.3. Using input streams read message given by server and print it.4. Using input streams, get message from user to be given to the server.5. Use output streams to write message to the server.6. Stop the program



PROGRAM FOR TALK SERVER:import java.io.*;import java.net.*;Public class talk server{Public static void main (String args []) throws Exception{Server Socket ecsvr=null;String line1, line 2;Data Input Stream dis =null;Print Stream pts=null;Socket cls ckt=null;Buffered Reader in1=null;Server =new Server Socket(9999);System. out. Println ("TALK SERVER");System. Out. println ("----------------------");clsckt= ecsvr. accept ();dis =new Data Input Stream (cls ckt. Get Input Stream ());pts =new Print Stream(cls ckt. get Output Stream());System. Out. Println ("Node successfully connected..");While (true){line1=dis. readLine ();System. Out .println("Message Received");System. out. println("The Message ="+line1);in1=new Buffered Reader (new Input Stream Reader (System. in));line2=in1.readLine ();if(line2.equals("end")){break;}pts. println (line2);pts. Flush ();System .out. println ("Message sent successfully");}dis. close();pts. close();}}



PROGRAM FOR TALK CLIENT:

import java.io.*;import java.net.*;public class talk client{public static void main(String args[]){Print Writer out=null;String line1;Buffered Reader networkln=null;try{Socket the Socket=new Socket("LocalHost",9999);networkln=new Buffered Reader(new Input Stream Reader(theSocket. Get Input Stream ()));Buffered Reader userln=new Buffered Reader (new Input StreamReader (System .in));out=new Print Writer(the Socket .get Output Stream());System .out. Println ("TALK CLIENT");System. out .println("--------------------");while(true){System.out.println ("send message to server: ");String the Line=userln. Read Line ();if(the Line. equals("end"))break;out. Println (the Line);out .flash();System. Out. Println ("message sent successfully");System. Out. Println (" ");System. out .println("message received from talk server:"+networkln. ReadLine ());} }Catch (IO Exception (e){System.err. println (e);} try{if(networkln!=null)network ln. close ();if(out!=null)Out. Close ();} catch (Exception e){System.err. println (e);} }



OUTPUT:TALK server

C:\Documents and Settings\Vvit staff>cd\C:\>cd D:\Sasi\JavaD:\Sasi\Java> set path=c:\program files\java\jdk1.6.0_02\binD:\Sasi\Java>javac talkerver.javaD:\Sasi\Java>java talk server

TALK SERVER----------------------Node successfully connected.Message ReceivedThe Message =HAIHI..Message sent successfullyMessage ReceivedThe Message =HOW ARE YOUI AM FINEMessage sent successfullyMessage ReceivedThe Message =K BYEendD:\Sasi\Java>

TALK Client

C:\Documents and Settings\Vvit staff>cd\C:\>cd D:\Sasi\JavaD:\Sasi\Java> set path=c:\program files\java\jdk1.6.0_02\binD:\Sasi\Java>javac talkclient.javaD:\Sasi\Java>java talk client

TALK CLIENT--------------------send message to server: HAImessage sent successfullymessage received from talk server: HI..send message to server: HOW ARE YOUmessage sent success fullmessage received from talk server: I AM FINEsend message to server: K BYEmessage sent successfullysend message to server:endD:\Sasi\Java>



RESULT:

Thus the java Socket Program for Talk Commands is executed and output is verified

successfully.



EX.NO:9

DATE:

IMPLEMENTATION OF DISTANCE VECTOR ROUTING ALGORITHM

AIM:To simulate the distance vector routing protocol to maintain routing tables as the traffic and

topology of the network changes using LAN-T software.

APPARATUS REQUIERD:

• LTS-01 trainer kit and LAN-T Software.

• 2 Computers with Windows XP and Ethernet port available on them.


PROCEDURE:

1. Double click on LAN-T Routing Simulator icon from the desktop.

2. Click load button and browse open C:\Lantrain\Config\ linear.txt.



3. Click configure button and select Distance vector algorithm.

4. The icon in the screen represents the nodes and the green colour line represents the path

and the values inside the braces represents the ‘Forward and Reverse’ weights.



5. Click on the node icon to obtain the message window.

6. The above picture shows the nodes and its routing table.



7. Observe the routing table showing no route to some of the destinations even though there is a

physical connection. This is because the routing table of the corresponding nodes are not been

updated since there is no hopping. To update the routing table click button.



8. Hopping is done by clicking run button.

9. Now, after several hopping the routing table gets updated. The number of hopping

increases as the number of nodes increases.

10. Click the green color line lying between N3 and N4.



11. Enter the forward and reverse weight as ‘-1’ in order to disconnect N4 from the other nodes.



12. Now observe the routing table.

.



13. Now, observe the no changes in the routing table, as they are not Updated Click button to

update the routing table.

14. Even after several hopping the routing tables of N0, N1, N2, N3 shows the path and

weight to N4.

RESULT:

Thus the simulation of the distance vector routing protocol to maintain routing tables asthe traffic and topology of the network changes has been verified.



EX.NO:10

DATE:

IMPLEMENTATION OF LINK STATE ROUTING ALGORITHM

AIM:

To simulate the link state routing protocol to maintain routing tables as the traffic and topology

of the network change by using LAN-T Software.

APPARATUS REQUIERD:




PROCEDURE:

1. Double click on LAN-T Routing Simulator icon from the desktop.

2. Click button and browse open C:\Lantrain\Config\ linear.txt.



3. Click configure button and select link state algorithm.

4. Click on the nodes to obtain the routing table.



5. Click the single step button to update the routing table and routing table of entire nodes

gets updated after a single hopping.

Count to Infinity problem:

6. Click on the green colour line lying between N3 and N4.



7. Enter forward and reverse weights as -1 to disconnect N4 from the other nodes.

8. Observe the routing table. The values are not changed as it’s not updated.

9. Click the single step button.

10. Now you could see the routing table for each nodes been updated.



MODEL OUTPUT:

RESULT:

Thus the simulate the link state routing protocol to maintain routing tables as the traffic

and topology of the network changes has been verified.



EX.NO:11

DATE:

IMPLEMENTATION AND STUDY THE PERFORMANCE OF NETWORK WITHCSMA / CA PROTOCOL

AIM:

To Implement the CSMA/CA protocol for packet communication between a number of nodes

connected to a common bus using LAN-T Software.

APPARATUS REQUIERD:




PROCEDURE:

1. Click on the MAC Experiment icon twice from the desktop on both PC’s.

2. Click the Configuration button in the window in both the PC’s.

PC SERVER 1



PC SERVER2




4. Run the experiment by clicking button or by choosing RUN Start from each application.

5. View the statistics window for results. To view the statistics window click on button. Only

Tx packets and collision count are taken into account for MAC calculation

PC 1 PC 2

Node ID 0 on config menu 1 and1 on config menu 2


Protocol ALOHA Protocol CSMA/CDBaud Rate 8Kbps (At both the config

menu and NEU)Baud Rate 8Kbps (At both the config

menu and NEU)

Duration 100s Duration 100s

Packet Length 100 bytes Packet Length 100 bytes

Bit Delay 0(at NEU) Bit Delay 0(at NEU)

Direction Sender Direction Receiver

My address 1 My address 2 on config menu 1 and 3 onconfig menu 2



PC SERVER 1

PC SERVER 2

6. Note down the readings once the experiment is completed.

7. Repeat the above steps for various values of ta.

8. Calculate the Practical offered load from the below given formula and plot the graph

between the practical Offered load and Throughput.

9. Repeat the experiments for various values of Packet length, Node, Data rate and Bit delay.



Calculation of generated load :

Equation:

N * PG = --------------

C * ta

G is the generated load in the network.N is the number of transmitting nodes. For example, 4 nodes (using 2 computers)P is the packet length expressed in bits; say 100 bytes (800 bits).C is the data rate normally set as 8kbs, which is selected in the NEU.ta is the inter packet delay expressed in seconds; the time interval between two consecutive

packets generated.

Calculation of Throughput (X) from the obtained readings:

Successfully transmitted packet by a node = Tx Packets - Collision Count

(Sum of Successfully Tx packet in all the nodes * Packet Length * 8)X = ---------------------------------------------------------------------------------------

(Duration of Experiment * Data ra

Calculation of Theoretical Throughput:

G(1+G+aG(1+G+aG/2))e-G(1+2a)X = --------------------------------------------------

G (1+2a)-(1-e-aG)+(1+aG)e-G(1+a)

a = (end to end bit delay in bits) / (Packet length in bits) = (bit delay*N) / (P)

Calculation of Offered load:

(Sum of Tx packets in all the nodes * Packet Length * 8)G = --------------------------------------------------------------------------




MODEL GRAPH:

MODEL TABULATION:

For bit delay = 1

IPD Tx1 Tx 2 Tx 3 Tx 4G – PracticalOffered Load

X –ThroughputTheoreticalThroughput

RES ULT :

Thus the Implementation of the CSMA/CA protocol for packet communication between

a numbers of nodes connected to a common bus data has been verified.



EX.NO:12

DATE:

IMPLEMENTATION AND STUDY THE PERFORMANCE OF NETWORK WITHCSMA/CD PROTOCOLS

AIM:

To Implement the CSMA/CD protocol for packet communication between a number of nodes

Connected to a common bus using LANT-T software.

APPARATUS REQUIERD:




PROCEDURE:

1. Click on the MAC Experiment icon twice from the desktop on both PC’s.




4. Run the experiment by clicking button or by choosing RUN _ start from each application.

5. View the statistics window for results. To view the statistics window click on button.

only Tx packets and successfully transmitted packets are taken into account for CSMA/CD

calculation.





9. Repeat the experiment for various values of Packet length, Node and Data rate.




Calculation of Throughput for CSMA/CD protocol:

Equation:

N * PG= --------------

C * ta

G is the generated load in the network.N is the number of transmitting nodes. For example, 4 nodes (using 2 computers)P is the packet length expressed in bits; say 100 bytes (800 bitsC is the data rate normally set as 8kbs, which is selected in the NEU.ta is the inter packet delay expressed in seconds; the time interval between two consecutivePackets generated


Successfully transmitted packet by a node = Tx Packets - Collision Count

(Sum of Successfully Tx packet in all the nodes * Packet Length * 8)X = -------------------------------------------------------------------------------------------


Calculation of Offered load:

(Sum of Offered load count in all the nodes * Packet Length * 8)G = ----------------------------------------------------------------------------------


PC 1 PC 2Node ID 0 on config menu 1 and

1 on config menu 2Node ID 0 on config menu 1 and

1 on config menu 2Protocol CSMA/CD Protocol CSMA/CDBaud Rate 8Kbps (At both the config

menu and NEU)Baud Rate 8Kbps (At both the config

menu and NEU)Duration 100s Duration 100sPacket Length 100 bytes Packet Length 100 bytesBit Delay 0(at NEU) Bit Delay 0(at NEU)Direction Sender Direction ReceiverNo of packets 4 No of packets 4



MODEL GRAPH :

MODEL TABULATION:

IPD Tx1 Tx 2 Tx 3 Tx 4 G – PracticalOffered Load

X -Throughput TheoreticalThroughput

RESULT:

Thus the Implementation of the CSMA/CD protocol for packet communication between a

numbers of Nodes connected to a common bus has been verified.



EX.NO:13

DATE:

IMPLEMENTATION OF DATA ENCRYPTION AND DECRYPTION

AIM:

To implement the Encryption and Decryption of a file using RC4 algorithm.

APPARATUS REQUIERD:

Java JDK 5.0.

Personal computer.

PROCEDURE:

Initial Setup:

1. Install Java JDK 5.0.

2. Browse C:\Lantrain\DataSecurity.

3. Copy the RC4 folder and three class files (Connect, RC4Client, and Server)

and paste it into the Java\jdk1.5\bin folder in both the server and client PC’s.

Setting up the Server:

1. Open the command prompt window (Start _Run _ type cmd).

2. Browse the java bin folder.

3. Type java Server to run the server.

Encrypting a file:

1. Open command prompt in the client side.

2. Browse the java bin folder.

3. Type java RC4Client.

4. Enter the IP address of the server.

5. Enter the mode of operation.

6. Enter the Encryption key not more than 5 characters.

7. Enter the path name of the file to be encrypted. (For e.g.: c:\\abc.txt)

8. Type YES if you like to close the session or type NO if you like to continue decrypting the

Cipher text.



9. The encrypted text is available in c:\output.tx .Try to re-arrange the cipher text using any

crypt-analysis tool

Decrypting the Cipher text file:

1. Enter the mode of operation as DEC for decrypting the cipher text.

2. Enter the Decryption keys same as used for Encryption.

3. Enter the full path name of the file to be decrypted. (i.e., c:\\output.txt)

4. Find out the decrypted file in c:\\output.txt.

SETTING UP THE SERVER:



MODEL OUT PUTS OF ENCRYPTION:



MODEL OUTPUT OF DECRYPTION:

RESULT:

Thus the data encryption and decryption file using RC4 algorithm was studied and verified.



EX.NO:14

DATE:

STUDY OF NETWORK SIMULATOR (NS).AND SIMULATION OF CONGESTIONCONTROL ALGORITHMS USING NS

AIM:

To Study of Network simulator (NS) and Simulation of Congestion Control Algorithms

using NS Tool.

NET WORK SIMULATOR (NS2)Ns overview

Ns programming: A Quick start Case study I: A simple Wireless network Case study II: Create a new agent in Ns

Ns overview

Ns Status Periodical release (ns-2.26, Feb 2003) Platform support FreeBSD, Linux, Solaris, Windows and Mac

Ns functionalitiesRouting, Transportation, Traffic sources, queuingdisciplines, QoS

WirelessAd hoc routing, mobile IP, sensor-MACTracing, visualization and various utilitiesNS (Network Simulators)

Most of the commercial simulators are GUI driven, while some network simulators are CLIdriven. The network model / configuration describe the state of the network (nodes, routers, switches,and links) and the events (data transmissions, packet error etc.). An important output of simulations isthe trace files. Trace files log every packet, every event that occurred in the simulation and are used foranalysis. Network simulators can also provide other tools to facilitate visual analysis of trends andpotential trouble spots.

Most network simulators use discrete event simulation, in which a list of pending "events" isstored, and those events are processed in order, with some events triggering future events such as theevent of the arrival of a packet at one node triggering the event of the arrival of that packet at adownstream node.

Simulation of networks is a very complex task. For example, if congestion is high, thenestimation of the average occupancy is challenging because of high variance. To estimate the likelihoodof a buffer overflow in a network, the time required for an accurate answer can be extremely large.Specialized techniques such as "control varieties" and "importance sampling" have been developed tospeed simulation.



Examples of network simulatorsThere are many both free/open-source and proprietary network simulators. Examples of

notable network simulation software are, ordered after how often they are mentioned in researchpapers:

1. ns (open source)2. OPNET (proprietary software)3. NetSim (proprietary software)

Uses of network simulators

Network simulators serve a variety of needs. Compared to the cost and time involved in settingup an entire test bed containing multiple networked computers, routers and data links, networksimulators are relatively fast and inexpensive. They allow engineers, researchers to test scenarios thatmight be particularly difficult or expensive to emulate using real hardware - for instance, simulating ascenario with several nodes or experimenting with a new protocol in the network. Network simulatorsare particularly useful in allowing researchers to test new networking protocols or changes to existingprotocols in a controlled and reproducible environment. A typical network simulator encompasses awide range of networking technologies and can help the users to build complex networks from basicbuilding blocks such as a variety of nodes and links. With the help of simulators, one can designhierarchical networks using various types of nodes like computers, hubs, bridges, routers, switches,links, mobile units etc.

Various types of Wide Area Network (WAN) technologies like TCP, ATM, IP etc. and LocalArea Network (LAN) technologies like Ethernet, token rings etc., can all be simulated with a typicalsimulator and the user can test, analyze various standard results apart from devising some novelprotocol or strategy for routing etc. Network simulators are also widely used to simulate battlefieldnetworks in Network-centric warfare

There are a wide variety of network simulators, ranging from the very simple to the verycomplex. Minimally, a network simulator must enable a user to represent a network topology,specifying the nodes on the network, the links between those nodes and the traffic between the nodes.More complicated systems may allow the user to specify everything about the protocols used to handletraffic in a network. Graphical applications allow users to easily visualize the workings of theirsimulated environment. Text-based applications may provide a less intuitive interface, but may permitmore advanced forms of customization.

Packet lossOccurs when one or more packets of data travelling across a computer network fail to reach

their destination. Packet loss is distinguished as one of the three main error types encountered in digitalcommunications; the other two being bit error and spurious packets caused due to noise.

Packets can be lost in a network because they may be dropped when a queue in the networknode overflows. The amount of packet loss during the steady state is another important property of acongestion control scheme. The larger the value of packet loss, the more difficult it is for transport layerprotocols to maintain high bandwidths, the sensitivity to loss of individual packets, as well as tofrequency and patterns of loss among longer packet sequences is strongly dependent on the applicationitself.



Throughput

This is the main performance measure characteristic, and most widely used. In communicationnetworks, such as Ethernet or packet radio, throughput or network throughput is the average rate ofsuccessful message delivery over a communication channel. The throughput is usually measured in bitsper second (bit/s mbps), and sometimes in data packets per second or data packets per time slot Thismeasure how soon the receiver is able to get a certain amount of data send by the sender. It isdetermined as the ratio of the total data received to the end to end delay. Throughput is an importantfactor which directly impacts the network performance

DelayDelay is the time elapsed while a packet travels from one point e.g., source premise or network

ingress to destination premise or network degrees. The larger the value of delay, the more difficult it isfor transport layer protocols to maintain high band widths. We will calculate end to end delay

Queue LengthA queuing system in networks can be described as packets arriving for service, waiting for service

if it is not immediate, and if having waited for service, leaving the system after being served. Thusqueue length is very important characteristic to determine that how well the active queue managementof the congestion control algorithm has been working.

RESULT:

Thus the study of Network simulator (NS2) has discussed and studied.



EX. NO: 15

DATE:

NETWORK TOPOLOGY - TOKEN BUS

AIM:To implement the network topology by token passing access in token bus LAN using LAN-T Software.

APPARATUS REQUIERD:

• LTS-01 trainer kit and LAN-T software.



PROCEDURE:1. Click on the Token Bus icon twice from the desktop.


PC 1




Note: All the nodes have to be configured as ‘Senders’. Set the topology as ‘Bus’.

*CSMA/CA application is built on Aloha shell script and hence we select protocol as Aloha.



4. Run the experiment by clicking button or by choosing RUN start from each application.

Run the all the experiments at the same time.

5. Enter the THT time in all nodes and press the OK button first in the node, which has

the lowest Priority of my Address.

PC 1 PC 2



Protocol ALOHA Protocol ALOHA

Baud Rate 8Kbps (At both the configmenu and NEU)





Direction Sender Direction Sender



PC SERVER 2

6. Set the Token Holding Time (THT) (say 2000 ms).

7. View the statistics window for results. To view the statistics window, click run button.




between the Practical Offered load and Throughput.

11. Repeat the experiment for various values of Packet length, Node, Data rate.

12. Repeat the above steps, while running the experiment set the BER to 10-2 or

try to stop one of the nodes and observe the behavior and explain the same.



Calculation of the generated load:

N * PG = ------

C * ta

G is the generated load in the network.

N is the number of transmitting nodes. For example, 4 nodes (using 2 computers)

P is the packet length expressed in bits; say 100 bytes (800 bits).

C is the data rate normally set as 8kbs, which is selected in the NEU.

ta is the inter packet delay expressed in seconds;.


(Sum of Tx packet in all the nodes * Packet Length * 8)X = -----------------------------------------------------------------------------


Calculation of the Offered load:

N * PG = ------

C * ta

G – Offered loadN – Number of nodesP – Packet length in bitsC – Data rate in bits/secta – Inter packet delay in millisecs.



MODEL GRAPH:

MODEL TABULATION:

IPD Tx 1 Tx 2 Tx 3 Tx 4 G – OfferedLoad

X –Throughput

Avg Delay

RESULT:

Thus the implementation of the token passing access in token bus-lan has been calculated and

verified.



EX. NO: 16

DATE:

NETWORK TOPOLOGY - TOKEN RING

AIM:To implement the token passing access in Token Ring by using LAN-T software.

APPARATUS REQUIERD:

• LTS-01 trainer kit and LAN-T software.



PROCEDURE:1. Click on the Token Ring icon twice from the desktop.


PC SERVER 1 PC SERVER 2




Note: All the nodes have to be configured as ‘Senders’. Set the topology as ‘Ring’3. Click OK button and Download the driver to the NIU using the BOOT button command. Booting

from anyone of the applications is enough.

4. Run the experiment by clicking button or by choosing RUN Start from each application. Run the

all the experiments at the same time.

5. View the statistics window for results. To view the statistics window, click run button.

6. Set the Token Holding Time (THT) (say 2000 ms).


PCSERVER 1 PC SERVER 2

PC 1 PC 2



Protocol RING Protocol RING






Direction Sender Direction Sender






10. Repeat the experiment for various values of Packet length, Node, Data rate.

11. Repeat the above steps, while running the experiment set the BER to 10-2 or

try to stop one of the nodes and observe the behavior and explain the same.

Calculation of the generated load:

N * PG = ------

C * ta

G is the generated load in the network.

N is the number of transmitting nodes. For example, 4 nodes (using 2 computers)

P is the packet length expressed in bits; say 100 bytes (800 bits).

C is the data rate normally set as 8kbs, which is selected in the NEU.

ta is the inter packet delay expressed in seconds; the time interval between two consecutive packets

generated.


(Sum of Tx packet in all the nodes * Packet Length * 8)X = -----------------------------------------------------------------------------


Calculation of the Offered load:

N * PG = ------

C * ta

G – Offered loadN – Number of nodesP – Packet length in bitsC – Data rate in bits/sec

ta – Inter packet delay in millisecs.



MODEL GRAPH:

MODEL TABULATION:

IPD Tx 1 Tx 2 Tx 3 Tx 4G –

OfferedLoad

X –Throughput

Avg Delay

RESULT:

Thus the implementation of the token passing access in Token ring has been calculated and

verified.



EX. NO: 17

DATE:

IMPLEMENTATION OF HIGH LEVEL DATA LINK CONTROL

AIM:

To write a c program to implement a data link control for bit stuffing method by using C-editor.

APPARATUS REQUIERD:

C -editor

Standalone desktop.

PROCEDURE:


2. Open C-editor.

3. Type the C program.

4. Save the program with file name ext .c.

5. Run the program.

6. If any error occurs in the program correct the error and again run the program.

7. Enter the data of message bit.

8. Check the entered data.




PROGRAM FOR DATA LINK CONTROL:

#include<stdio.h>

#include<conio.h>void charc(void);void main(){int choice;while(1){printf("\n\n\n1.character stuffing");printf("\n\n2.exit");printf("\n\n\n enter choice");scanf("%d",& choice);printf("%d", choice);if(choice>2)printf("\n\n invalid option....please renter");switch(choice){case 1:charc ();break;case 2:exit(0);}}}void charc(void){char c[50],d[50],t[50];int i,m,j;clrscr();printf("enter the number of characters\n");scanf("%d",&m);printf("\n enter the characters\n");for(i=0;i<m+1;i++)scanf("%c",&c[i]);}printf("\n original data\n");for(i=0;i<m+1;i++)printf("%c",c[i]);

d[0]='d';d[1]='l';



d[2]='e';d[3]='s';d[4]='t';d[5]='x';for(i=0,j=6;i<m+1;i++,j++){

if((c[i]=='d'&&c[i+1]=='l'&& c[i+2]=='e')){d[j]='d';j++;d[j]='l';j++;d[j]='e';j++;m=m+3;}d[j]=c[i];}m=m+6;m++;d[m]='d';m++;d[m]='l';m++;d[m]='e';m++;d[m]='e';m++;d[m]='t';m++;d[m]='x';m++;printf("\n\n transmitted data: \n");for(i=0;i<m; i ++){

printf ("%c",d[i]);}for(i=6,j=0;i<m-6;i++,j++){

if(d[i]=='d'&&d[i+1]=='l'&&d[i+2]=='e'&&d[i+3]=='d'&&d[i+4]=='l'&&d[i+5]=='e')i=i+3;t[j]=d[i];}printf("\n\n received data:");



for(i=0;i<j; i++){printf("%c", t[i]);

}}

MODEL OUTPUT:

RESULT:

Thus the program for implementation of a data link control for bit stuffing method is executed

and output is verified successfully.

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